Catriona Clemmesen-Bockelmann

How does climate change alter the ocean? How can the ocean provide food for our planet’s growing population? Catriona Clemmesen-Bockelmann, fisheries biologist at GEOMAR Helmholtz Centre for Ocean Research Kiel and her colleagues investigate, how ocean acidification and warming affect economically important fish species.

Eggs and larvae appear to be most sensitive – and only those animals which survive this phase will be available in fisheries later on. An experiment and model calculations on cod revealed that the mortality of fish larvae due to ocean acidification was around twice as high as under normal conditions. This will reduce stocks to about a quarter of today’s amounts.

“The results we found are so shocking and so frightening that we must not ignore them”, says Catriona Clemmesen. If we keep fish stocks as high as possible, they will be more able to deal with future stressors.